When a document is rendered in pdf, empty lines are rendered as whitespace, rather than as a line return.
This results in a 'functional' omission of the 'empty line' in pgp messages.
The standard for open pgp messages, is that there needs to be an empty line between the last line of the pgp header, and the beginning of the radix 64 armor of the pgp message block.
This is primarily for aesthetic effect, but some implementations will not process the message if the empty line is absent.

(All versions of PGP will decrypt/verify the message even in the absence of the 'empty line',
while earlier versions of GnuPG will give an error message of 'improper header' and halt further processing.
The 1.4.2 version 'does' accept the message in absence of the empty line.)

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